1. Field of Invention
The invention relates to an apparatus for processing timber to be used in the construction of a log home. More particularly, it relates to a multi-axis robotic apparatus for performing multiple processes on a log to be used in the construction of a log home.
2. Description of the Related Art
Log construction continues to be a popular form of construction for structures such as, for example, homes. However, many log structures look very little like the early log structures which were constructed of logs which were hand-hewn from the trunks of trees. In this regard, in traditional log construction the tree trunks used for logs underwent minimal modification before incorporation into a structure. Accordingly, the height or vertical dimensions of the logs when disposed horizontally in a log structure varied along their lengths as a consequence of the natural inconsistent diameters of the trees from which the logs were derived. Of course, variations in the vertical dimensions of the logs along their lengths resulted in gaps of varying widths between adjacent logs, and these gaps were filled with a hardenable chinking material such as clay or mud. Thus, in traditional log construction not only did the vertical dimensions of the logs vary along their lengths, but the chinking joints between the logs varied in height along their lengths.
Of course, the variation in the vertical dimension of the logs along their length made construction difficult; and the resulting gaps between the logs, although they could be filled with chinking material, were undesirable. Thus, in recent years, logs used in the construction of log structures have been milled to define a uniform height or vertical dimension along their lengths. Further, rigid spacing blocks are generally disposed between the logs to span uniform gaps between the logs, with a decorative coating of chinking material being provided on exposed surfaces of the spacing blocks to give the appearance of a traditional chinking joint. However, given the uniformly dimensioned logs and uniformly dimensioned gaps there between, the appearance of the traditional log structure is lost. Examples of known log construction methods and techniques are disclosed in U.S. Pat. Nos. 5,253,458; 5,020,289; 4,951,435; 4,871,003; 4,527,981; 4,519,429; 4,509,571; 4,391,067; 4,230,163; 4,168,675; 4,167,961; 4,143,692; 4,082,129; and 3,957,095.
In addition to these references, the inventor of the invention disclosed herein, invented a Log Fabricating Process and Log for the Construction of Log Structures as disclosed in U.S. Pat. No. 5,505,028, (“the '028 patent”), issued to Randy K. Giles on Apr. 9, 1996. The '028 patent disclosed a log and an associated fabricating process for fabricating logs used in the constructions of log structures wherein the resulting log structure gives the appearance of a traditional log structure. Given that these logs have an irregular profile, i.e. varying in diameter along its length, those skilled in the art recognize that processing these logs on state-of-the-art saws, such as is depicted in the '028 patent, presents challenges in keeping the log aligned with a saw blade. Further, these type of logs undergo a series of different types of processes, requiring moving the log from one machine to another. FIGS. 1 and 2 illustrate a prior art process of preparing a log for a log home according to the teachings of the '028 patent, and an exemplary log home. Specifically, FIG. 1 illustrates the process for preparing a log as taught by the '028 patent, owned by a common assignee of the present invention. In accordance with the teachings of the '028 patent, log 10 has a first end 12 and a second end 14. Grooves 16 and 18 are cut into the log by a cutting device such as dado cutter 20. Dado cutter 20 is used to cut the longitudinal grooves 16 and 18, in accordance with the teachings of the '028 patent, such that the bottom surfaces 22 and 24 of the grooves 16 and 18 are substantially parallel to one another over the length of the log 10. Due to the varying vertical dimensions of the log 10 the resulting grooves 16 and 18 vary in depth along the length in the log 10. For example, with respect to the illustrated log 10, the grooves 16 and 18 are deeper at the first end 12 of the log 10 and become shallower toward the second end 14 as the vertical dimension of the log 10 decreases. Typically the depth of the grooves 16 and 18 varies between 0″ and 4″ along the length of the log 10; but a greater maximum depth can be used if desired. Further, it will be recognized by those skilled in the art that in order to keep the center line 26 of the log 10 a fixed distance from the fence 28, guide boards 30 are temporarily secured to log 10 and it is these guide boards 30 that engage fence 28. This “squares” the log 10 relative to the machine at the maximum width of the log 10.
Further, those skilled in the art will recognize that in the construction of a log home, such as illustrated in FIG. 2, the heights of the various courses of logs may vary from course to course. However, it is critical that the centerlines of the logs of each successive course be parallel. Further, those skilled in the art will recognize that there are a number of processes that must be performed on a log. And, traditionally, these different processes are performed on different machines, requiring loading a log onto a machine, executing the desired process, removing the log from a machine, and transporting the log from machine to machine.
What is missing from the art is a robotic apparatus for processing timber used in construction of a log home that is that is adapted to compensate for the irregular profile of the without the use of guide boards. What is further missing from the art is a robotic apparatus that is adapted to perform multiple cutting operations on a log without requiring moving the log from one machine to another.